Re: [9fans] VGA and laptops

[nigel@9fs.org]

> I do have a question though, wasn't VESA compliance supposed to do away with
> these problems

It does, if you feel like you can put your trust in someone's BIOS.... Making a call
into the BIOS is hairy in that you have no way to make it adhere to the particular
set of rules which your operating system makes on drivers, e.g. time spent with
interrupts off, how long spent spinning waiting for VBE etc..

As a result, one can imagine using it as a means to get the right screen mode at
the start, but you would never think of making calls to it for accelerated drawing.
So you can get a frame buffer and then bit bash, which I accept is a whole lot
better than nothing.

However, if you want an accelerated driver, then there are typically interrelationships
between the screen mode, and the blitter, so VESA is not much help. Putting it
another way, to be able to accelerate a chipset, you would probably need
to understand every setting that VESA makes; if so, then why use it?

VNH's native Inferno uses VESA calls to initialise the screen mode.